DETROIT » General Motors Co. said on Friday that it is recalling more than 4,000 of its 2012 Chevrolet Sonic subcompact cars to check for missing brake pads.

The possibility that some Sonics could be missing an inner or outer brake pad was discovered during warranty service for a rental vehicle customer. GM said the problem "is expected to exist in very few cars," and there are no known crashes or injuries related to the issue. A missing pad could require longer stopping distance, and contribute to a crash.

The recall involves 4,296 of GM’s 2012 Sonics sold in the U.S. The affected models are from the Orion Township, Mich., assembly plant, where the Sonic is built for sale in the U.S. and Canada.

Dealers will inspect the front brakes for missing inner or outer pads and, if a pad is missing, install new pads. If needed, a new brake caliper or brake rotor, or both, will also be installed. Affected customers will receive dealer letters beginning Jan. 14.